And while you are at it, here is another one effective immediately (actually since July 1st, 2022), which can be seen as related, as it also needs to be accessible for guests:
New cancellation process for subscriptions required
A new law specifies in detail how online contracts like Invision Community subscriptions can be cancelled when services are offered to people in Germany. The current implementation is not sufficient at all.
The law text (in German): https://www.gesetze-im-internet.de/bgb/__312k.html
Good English article about it: https://www.nitrobox.com/en/cancellation-button-bgb-312k-explained/
The article above provides a blueprint of how the cancellation must be performed. As explained in the article, the law is extremely precise in what is required. Specific buttons which easily accessible, specific fields in the form, a confirmation with print-out capability, an automatic confirmation and ALL of it accessible to guests as well.